Add layout functionality to mailers.

Mailer layouts behaves just like controller layouts, except layout names need to
have '_mailer' postfix for them to be automatically picked up.

actionmailer/CHANGELOG

@@ -1,3 +1,8 @@
+* Add layout functionality to mailers [Pratik]
+
+  Mailer layouts behaves just like controller layouts, except layout names need to
+  have '_mailer' postfix for them to be automatically picked up.
+
 *2.1.0 (May 31st, 2008)*
 
 * Fixed that a return-path header would be ignored #7572 [joost]

actionmailer/lib/action_mailer/base.rb

@@ -246,7 +246,10 @@ module ActionMailer #:nodoc:
   #   +implicit_parts_order+.
   class Base
     include AdvAttrAccessor, PartContainer
-    include ActionController::UrlWriter if Object.const_defined?(:ActionController)
+    if Object.const_defined?(:ActionController)
+      include ActionController::UrlWriter
+      include ActionController::Layout
+    end
 
     private_class_method :new #:nodoc:
 
@@ -362,6 +365,7 @@ module ActionMailer #:nodoc:
 
     # The mail object instance referenced by this mailer.
     attr_reader :mail
+    attr_reader :template_name, :default_template_name, :action_name
 
     class << self
       attr_writer :mailer_name
@@ -530,6 +534,7 @@ module ActionMailer #:nodoc:
         @content_type ||= @@default_content_type.dup
         @implicit_parts_order ||= @@default_implicit_parts_order.dup
         @template ||= method_name
+        @default_template_name = @action_name = @template
         @mailer_name ||= self.class.name.underscore
         @parts ||= []
         @headers ||= {}
@@ -546,7 +551,22 @@ module ActionMailer #:nodoc:
         if opts[:file] && (opts[:file] !~ /\// && !opts[:file].respond_to?(:render))
           opts[:file] = "#{mailer_name}/#{opts[:file]}"
         end
-        initialize_template_class(body).render(opts)
+
+        begin
+          old_template, @template = @template, initialize_template_class(body)
+          layout = respond_to?(:pick_layout, true) ? pick_layout(opts) : false
+          @template.render(opts.merge(:layout => layout))
+        ensure
+          @template = old_template
+        end
+      end
+
+      def default_template_format
+        :html
+      end
+
+      def candidate_for_layout?(options)
+        !@template.send(:_exempt_from_layout?, default_template_name)
       end
 
       def template_root

actionmailer/test/fixtures/auto_layout_mailer/hello.html.erb

@@ -0,0 +1 @@
+Inside

actionmailer/test/fixtures/explicit_layout_mailer/logout.html.erb

@@ -0,0 +1 @@
+You logged out

actionmailer/test/fixtures/explicit_layout_mailer/signup.html.erb

@@ -0,0 +1 @@
+We do not spam

actionmailer/test/fixtures/layouts/auto_layout_mailer.html.erb

@@ -0,0 +1 @@
+Hello from layout <%= yield %>

actionmailer/test/fixtures/layouts/spam.html.erb

@@ -0,0 +1 @@
+Spammer layout <%= yield %>

actionmailer/test/mail_layout_test.rb

@@ -0,0 +1,78 @@
+require 'abstract_unit'
+
+class AutoLayoutMailer < ActionMailer::Base
+  def hello(recipient)
+    recipients recipient
+    subject    "You have a mail"
+    from       "tester@example.com"
+  end
+
+  def spam(recipient)
+    recipients recipient
+    subject    "You have a mail"
+    from       "tester@example.com"
+    body       render(:inline => "Hello, <%= @world %>", :layout => 'spam', :body => { :world => "Earth" })
+  end
+
+  def nolayout(recipient)
+    recipients recipient
+    subject    "You have a mail"
+    from       "tester@example.com"
+    body       render(:inline => "Hello, <%= @world %>", :layout => false, :body => { :world => "Earth" })
+  end
+end
+
+class ExplicitLayoutMailer < ActionMailer::Base
+  layout 'spam', :except => [:logout]
+
+  def signup(recipient)
+    recipients recipient
+    subject    "You have a mail"
+    from       "tester@example.com"
+  end
+
+  def logout(recipient)
+    recipients recipient
+    subject    "You have a mail"
+    from       "tester@example.com"
+  end
+end
+
+class LayoutMailerTest < Test::Unit::TestCase
+  def setup
+    set_delivery_method :test
+    ActionMailer::Base.perform_deliveries = true
+    ActionMailer::Base.deliveries = []
+
+    @recipient = 'test@localhost'
+  end
+
+  def teardown
+    restore_delivery_method
+  end
+
+  def test_should_pickup_default_layout
+    mail = AutoLayoutMailer.create_hello(@recipient)
+    assert_equal "Hello from layout Inside", mail.body.strip
+  end
+
+  def test_should_pickup_layout_given_to_render
+    mail = AutoLayoutMailer.create_spam(@recipient)
+    assert_equal "Spammer layout Hello, Earth", mail.body.strip
+  end
+
+  def test_should_respect_layout_false
+    mail = AutoLayoutMailer.create_nolayout(@recipient)
+    assert_equal "Hello, Earth", mail.body.strip
+  end
+
+  def test_explicit_class_layout
+    mail = ExplicitLayoutMailer.create_signup(@recipient)
+    assert_equal "Spammer layout We do not spam", mail.body.strip
+  end
+
+  def test_explicit_layout_exceptions
+    mail = ExplicitLayoutMailer.create_logout(@recipient)
+    assert_equal "You logged out", mail.body.strip
+  end
+end

actionpack/lib/action_controller/layout.rb

@@ -216,7 +216,7 @@ module ActionController #:nodoc:
     # object). If the layout was defined without a directory, layouts is assumed. So <tt>layout "weblog/standard"</tt> will return
     # weblog/standard, but <tt>layout "standard"</tt> will return layouts/standard.
     def active_layout(passed_layout = nil)
-      layout = passed_layout || self.class.default_layout(response.template.template_format)
+      layout = passed_layout || self.class.default_layout(default_template_format)
       active_layout = case layout
         when String then layout
         when Symbol then send!(layout)
@@ -276,5 +276,9 @@ module ActionController #:nodoc:
       rescue ActionView::MissingTemplate
         false
       end
+
+      def default_template_format
+        response.template.template_format
+      end
   end
 end